The present invention relates to improving conveying systems for transporting dynamo-electric machine components between a series of processing machines of an automatic, parallel processing, production line, and for delivering such components to a selected one of the series of processing machines for processing. More particularly, the present invention relates to conveying systems for transporting dynamo-electric machine components (e.g., electric motor parts) having magnetic cores between a main conveyor and a selected one of a series of processing machines working in parallel along the main conveyor. The present invention further relates to load/unload devices for transferring dynamo-electric machine components between the main conveyor and the selected processing machines. Dynamo-electric machine components are loaded directly from the main conveyor line onto a load/unload device, and from the load/unload device onto the selected processing machine in a time-efficient manner. The load/unload device has two component holders (e.g., collets) movably mounted on a base platform for alternate alignment for loading and unloading of dynamo-electric machine components. The load/unload device moves between the main conveyor and the selected processing machine while the central axis of the load/unload device preferably remains fixed.
Automatic manufacturing lines for processing dynamo-electric machine components having a magnetic core (hereinafter "components") typically transport the components between a variety of machines. (By "magnetic core" it is meant that the core is magnetizable, not that it is necessarily magnetized at all times.) For example, armatures are conveyed to such machines as winding machines and fusing machines. The present invention is specifically related to conveying such components as armatures to any type of machinery or processing apparatus that characteristically is used in parallel with at least one other identical machine on a particular conveyor section. These machines typically have slower production rates than machinery that is not used in parallel production lines (i.e., machinery in manufacturing lines where only one machine of a particular type is present on the line). These machines also usually require the components to be removed from the pallets on which they are conveyed in order to be processed. Once processing has been accomplished, the component is returned to an empty pallet for transport to other downstream machines of the manufacturing line.
One example of a conveying system is shown in FIG. 1. A main conveyor section 100 transports pallets carrying components such as armatures to any one of the machines 102, 104, and 106 of the same type. Additional conveyors 112, 114, and 116 are placed in front of respective machines 102, 104, and 106 for conveying to a selected machine components to be processed. Transfer devices 122, 124, and 126 remove pallets carrying components to be processed from main conveyor section 100 and transfer the pallets to the additional conveyors 112, 114, and 116, respectively.
Once a pallet is on one of additional conveyors 112, 114, 116, the component it is carrying can be transferred to a corresponding machine 102, 104, 106 for processing. The pallet can then receive a processed component from the machine along which the pallet is conveyed. After the pallet receives a processed component, the pallet can move to the downstream transfer device 132, 134, 136 associated with the additional conveyor on which the pallet is conveyed, and be returned to main conveyor section 100. The pallet, now carrying a processed component (such as a wound armature), is subsequently transferred to further conveyor section 110.
The pallets that carry the components for processing are typically provided with coding devices which indicate the processing condition of the component being carried. More precisely, these devices indicate whether a component has or has not been processed by one of machines 102, 104, 106. Writing devices may also be used to change the coding information so that the device indicates that the component has been processed.
Devices for reading the coding devices are placed before transfer devices 122, 124, and 126 to determine whether a pallet needs to be transferred to an associated machine for processing. If the pallet need not be transferred (because the component it is carrying has already been processed), the pallet travels to the end of main conveyor section 100 for transfer to further conveyor section 110. Reading of the coding device occurs each time a pallet reaches one of transfer devices 122, 124, 126. The pallets are stopped against an abutment surface in order to have their coding devices read while the transporter belts continue to move. Before a pallet is transferred to further section 110, another reading of the coding device is performed to determine whether the pallet is carrying an unprocessed component and needs to be returned to the beginning of main conveyor section 100.
Additional conveyor sections 112, 114, and 116 are provided with devices for determining how many pallets are queued up on the selected conveyor waiting to deliver a component to a corresponding machine 102, 104, 106. If the number of pallets on a particular additional conveyor section is at the maximum, then transfer by the transfer device related to that particular section will not transfer a pallet to that section until a place for another pallet is created. Thus, pallets having components which need to be processed travel down main conveyor section 100 until they find a free additional conveyor section 112, 114, 116. If the pallet reaches the end of main conveyor section 100 without having found a free additional conveyor section (e.g., because machines 102, 104, and 106 are all occupied), then transfer device 140 transfers the pallet to return conveyor 142, and transfer device 144 returns the pallet to the beginning of main conveyor section 100. The pallet then once again attempts to find a free additional conveyor section 112, 114, 116, as described above.
A possible disadvantage of this type of conveying system in some situations is the delays that occur while pallets and components are transferred. When pallets are transferred by transfer devices 122, 124, 126, 132, 134, 136 between main conveyor section 100 and additional conveyor sections 112, 114, 116, pallets upstream of the pallet being transferred are halted to allow the transfer to occur. Loading and unloading of components between pallets on additional conveyor sections 112, 114, 116 and machines 102, 104, 106 occurs by stopping the pallet in front of the associated load/unload device 152, 154, 156, removing the component to be processed, and placing on the now empty pallet a processed component so that the pallet can be transferred back to main conveyor section 100 without waiting for completion of processing of the component it had delivered.
Another characteristic of systems of the type shown in FIG. 1 is that the additional conveyor sections tend to require additional floor space and may increase the maintenance requirements of the system. As shown in FIG. 1, five different conveyor sections must continue to run smoothly for the conveying system to be fully operational.
Finally, load/unload devices 152, 154, 156 may be regarded as relatively slow in transferring components between additional conveyor lines 112, 114, 116, and machines 102, 104, 106, respectively.
A second type of conveying system is shown in FIG. 2. A main conveyor 200 transports pallets carrying components to a number of machines, such as winder 202, in a parallel processing system. When a pallet carrying a component to be processed approaches an available machine, the pallet is transferred to a secondary conveyor 210, which is preferably perpendicular to main conveyor 200. From secondary conveyor 210, the component to be processed is transferred to a collet on carriage 220. Carriage 220 is positioned on slide 230, which is cantilevered from support 240. Slide 230 slides in direction 232 to bring carriage 220 adjacent secondary conveyor 210 in a plane spaced above the plane of secondary conveyor 210. As viewed in FIG. 2 the stopping point of slide 230 is below the depicted location of the pallet on secondary conveyor 210. The component on this pallet is then lifted off the pallet. Carriage 220 slides laterally on slide 230 along direction 222 to alternately align collet 226 with the pallet (to receive a component from the conveying system for processing) and to align collet 224 with the pallet (to return a processed component to the conveying system). Slide 230 slides along direction 232 to transport carriage 220 to winder 202 to load a processed component onto collet 224 (then aligned with winder 202). Carriage 220 then slides along direction 222 to deliver a component to be processed, carried by collet 226, to winder 202. Slide 230 then slides back to additional conveyor 210 to repeat the above steps.
Because this conveying system also uses additional conveyor lines 210 to which pallets are transferred, this system may also have the above-described possible disadvantages of time delays during pallet transfer, the necessity of additional floor space, and increased maintenance requirements. The length of travel of slide 230 also tends to be quite long.
A third type of a conveying system, described in Nussbaumer U.S. Pat. No. 4,718,533, does not use additional conveyor sections (such as those shown in FIG. 1). When a pallet needs to be loaded or unloaded at a particular machine, the pallet is lifted off the main conveyor so that pallets that need to reach a downstream portion of the conveyor line can travel beneath the lifting device. This system tends to require complicated pallet-lifting equipment.
In view of the foregoing, it would be desirable to provide a conveying system and method that would quickly and efficiently convey components to be processed through a manufacturing line, and transport the components between the means conveying the components and the machines in the manufacturing line.
It would also be desirable to provide a conveying system and method that would not require conveyor lines in addition to the main conveyor line or complicated pallet lifting equipment that may tend to increase machinery costs and require large areas of manufacturing plant floor space.
It would further be desirable to provide a load/unload device and method that quickly and efficiently transports components between a conveyor line and a processing machine.